package main

import(
	"fmt"
	"math"
)

type Vertex struct{
	X,Y float64
}

func (v *Vertex) Scale(f float64){
	v.X = v.X * f
	v.Y = v.Y * f
}

func (v *Vertex) Abs() float64{
	return math.Sqrt(v.X*v.X + v.Y*v.Y)
}

func main(){
	v := &Vertex{3,4}
	v.Scale(5)
	fmt.Println(v, v.Abs())
}
